Defrost fan control
A refrigeration module of a cold space chamber has a blower and an evaporator. A method of controlling the refrigeration module includes defrosting a coil of the evaporator to form a volume of warm air surrounding the coil. The method includes circulating a refrigerant through the evaporator after defrosting the coil, to cool the coil. The method includes operating the blower in a series of pulses to control introduction of the volume of warm air into the cold space chamber.
1 . A method of controlling a refrigeration module of a cold space chamber, the refrigeration module having a blower and an evaporator, the method comprising:
(a) defrosting a coil of the evaporator to form a volume of warm air surrounding the coil;
(b) circulating a refrigerant through the evaporator after (a) to cool the coil; and
(c) operating the blower in a series of pulses during (b) to control introduction of the volume of warm air to the cold space chamber, wherein (c) further comprises:
(c1) activating the blower for a first pulse of the series of pulses;
(c2) determining a temperature associated with the cold space chamber after (c1); and
(c3) determining that the temperature has increased by a threshold amount during the first pulse and ending the first pulse to deactivate the blower based at least in part on the determination.
2 . The method of claim 1 , wherein (a) comprises operating the refrigeration system to circulate the refrigerant through the coil at an elevated temperature.
3 . The method of claim 1 , wherein (c) comprises operating the blower at a first speed during each of the series of pulses, and wherein the method further comprises:
(d) operating the blower continuously at a second speed that is greater than the first speed, after (c).
4 . The method of claim 1 , wherein (c) comprises a series of alternating operations that include:
(c1) operating the blower to generate an airflow across the coil in a first direction; and
(c2) operating the blower or a further blower to generate an airflow across the coil in a second direction opposing the first direction.
5 . The method of claim 1 , wherein the refrigeration module comprises a cascade refrigeration assembly having a first refrigerant circuit and a second refrigerant circuit including the evaporator, and wherein (b) comprises circulating the refrigerant through the second refrigerant circuit including the evaporator.
6 . The method of claim 1 , wherein (c) further comprises increasing a time duration for each successive pulse of the series of pulses.
7 . The method of claim 1 , wherein (c2) further comprises determining the temperature by use of a temperature sensor that is mounted in a suction duct defined between the cold space chamber and the evaporator.
8 . The method of claim 1 , wherein (c) further comprises:
(c4) determining that the temperature has not increased above the threshold amount after a threshold period of time during a subsequent pulse of the series of pulses; and
(c5) ceasing the series of pulses based at least in part on (c4).
9 . A cold storage system comprising:
a housing defining a cold space chamber therein;
a refrigeration module configured to cool the cold space chamber, the refrigeration module including an evaporator and a blower configured to generate an airflow from the evaporator to the cold space chamber; and
a controller, communicatively coupled to the refrigeration module and configured to:
(a) defrost a coil of the evaporator to form a volume of warm air surrounding the coil;
(b) circulate a refrigerant through the evaporator after (a) to cool the coil; and
(c) activate the blower in a series of pulses during (b) to control introduction of the volume of warm air to the cold space chamber, wherein, the controller is further configured to:
(c1) activate the blower for a first pulse of the series of pulses;
(c2) determine a temperature associated with the cold space chamber after (c1); and
(c3) determine that the temperature has increased by a threshold amount during the first pulse and ending the first pulse to deactivate the blower based at least in part on the determination.
10 . The cold storage system of claim 9 , wherein (a) comprises operate the refrigeration system to circulate the refrigerant through the coil at an elevated temperature.
11 . The cold storage system of claim 9 , wherein (c) comprises operate the blower at a first speed during each of the series of pulses, and wherein the controller is further configured to:
(d) operate the blower continuously at a second speed that is greater than the first speed, after (c).
12 . The cold storage system of claim 9 , wherein (c) comprises a series of alternating operations that include:
(c1) operate the blower to generate an airflow across the coil in a first direction; and
(c2) operate the blower or a further blower to generate an airflow across the coil in a second direction opposing the first direction.
13 . The cold storage system of claim 9 , wherein the refrigeration module comprises a cascade refrigeration assembly having a first refrigerant circuit and a second refrigerant circuit including the evaporator, and wherein (b) comprises circulate the refrigerant through the second refrigerant circuit including the evaporator.
14 . The cold storage system of claim 9 , wherein (c) further comprises increase a time duration for each successive pulse of the series of pulses.
15 . A tangible, non-transitory, computer-readable media having instructions thereupon which, when executed by a processor, cause the processor to perform a method comprising:
(a) defrosting a coil of an evaporator to form a volume of warm air surrounding the coil;
(b) circulating a refrigerant through the evaporator after (a) to cool the coil; and
(c) operating a blower in a series of pulses during (b) to control introduction of the volume of warm air to a cold space chamber wherein (c) further comprises:
(c1) activating the blower for a first pulse of the series of pulses;
(c2) determining a temperature associated with the cold space chamber after (c1); and
(c3) determining that the temperature has increased by a threshold amount during the first pulse and ending the first pulse to deactivate the blower based at least in part on the determination.
16 . The tangible, non-transitory, computer-readable media of claim 15 , wherein (c) comprises operating the blower at a first speed during each of the series of pulses, and wherein the method further comprises:
(d) operating the blower continuously at a second speed that is greater than the first speed, after (c).
17 . The tangible, non-transitory, computer-readable media of claim 15 , wherein (c) comprises a series of alternating:
(c1) operating the blower to generate an airflow across the coil in a first direction in a first set of the series of pulses; and
(c2) operating the blower to generate an airflow across the coil in a second direction opposing the first direction in a second set of the series of pulses.
18 . The tangible, non-transitory, computer-readable media of claim 15 , wherein the method further comprises:
(d) adjusting a time duration of each of the series of pulses during (c).